Concerning the level of occlusion (as aforementioned, OPIXray [1]} splits the test data into three subsets, OP1, OP2, OP3, according to the level of occlusion), we can see in Table REF  that the proposed framework achieves the best performance at each occlusion level as compared to the second-best DOAM [1]} framework driven by the single-shot detector (SSD) [3]}.
